Background/Objectives. To illustrate characteristic electroencephalogram (EEG) features in patients prior to their first cardiac arrest. Methods. We identified 15 patients who suffered cardiac arrest during continuous EEG at our institution from June 2016 to June 2019. Eight patients were excluded due to co-administration of intravenous anesthetics (which may confound EEG) or if they had a previous prolonged cardiac arrest (>5 minutes) during the same hospitalization. We collected background information, analyzed the time span and vital signs between the initial background change and cardiac arrest. Results. The time span range (minutes) from initial background change to cardiac arrest was 4 to 483 (average 128.9), initial background change to suppression was 0 to 372 (average 75.6), suppression to cardiac arrest was 1 to 140 (average 53.3), suppression to complete suppression was 0 to 66 (average 20.4), and complete suppression to cardiac arrest was 1 to 111 (average 32.9). Three patients showed background changes more than 160 minutes before cardiac arrest. All patients showed progressive heart rate (HR) decline at or before the beginning of suppression on EEG. HR (beats/min) (mean ± SE) at background change, background suppression, complete suppression, and cardiac arrest was 86.3 ± 7.5, 63.9± 7.5, 36.0 ± 6.8, and 0, respectively. We found statistically significant HR changes (P < .05) between background change and complete suppression time points. Conclusions. Our data indicate that EEG pattern change can occur minutes to hours before the initial cardiac arrest. These patterns may be due to progressive cerebral ischemia. Further studies with broad-scale monitoring of vital signs and evoked potentials may help develop models for predicting cardiac insufficiency.

中文翻译：

---

心脏骤停前危重患者的脑电图特征：病例系列

背景/目标。说明患者首次心脏骤停前的特征性脑电图 (EEG) 特征。方法。我们确定了 15 名患者在 2016 年 6 月至 2019 年 6 月期间在我们机构的连续脑电图期间发生心脏骤停。 8 名患者因同时使用静脉麻醉药（可能会混淆脑电图）或之前有过长时间的心脏骤停 (> 5 分钟）在同一住院期间。我们收集了背景信息，分析了初始背景变化和心脏骤停之间的时间跨度和生命体征。结果。从初始背景变化到心脏骤停的时间跨度范围（分钟）为 4 到 483（平均 128.9），初始背景变化到抑制为 0 到 372（平均 75.6），抑制到心脏骤停为 1 到 140（平均 53.3），完全抑制的抑制率为 0 至 66（平均 20.4），完全抑制心脏骤停为 1 至 111（平均 32.9）。三名患者在心脏骤停前超过 160 分钟出现背景变化。所有患者在 EEG 抑制开始时或之前均表现出进行性心率 (HR) 下降。背景变化、背景抑制、完全抑制和心脏骤停时的 HR（搏动/分钟）（平均值 ± SE）分别为 86.3 ± 7.5、63.9 ± 7.5、36.0 ± 6.8 和 0。我们发现背景变化和完全抑制时间点之间具有统计学意义的 HR 变化 (P < .05)。结论。我们的数据表明，脑电图模式的变化可能会在初始心脏骤停前几分钟到几小时发生。这些模式可能是由于进行性脑缺血所致。